2024 RNC begins on heels of assassination attempt. Here's what to know.

Washington — Former President Donald Trump will officially become the GOP nominee for president at this week's Republican National Convention, days after surviving an assassination attempt .

The four-day event kicks off on Monday, just two days after a gunman opened fire at a Trump rally in Pennsylvania, grazing Trump's ear. Rally attendee Corey Comperatore, 50, was killed, and two others, identified as 57-year-old David Dutch and 74-year-old James Copenhaver, were wounded. The shooter, 20-year-old Thomas Matthew Crooks, was killed by a Secret Service sniper.

The attack has put federal, state and local law enforcement officials on even higher alert heading into the convention . Changes to the security measures were being planned after Trump was wounded at the Pennsylvania campaign rally.

What security measures are in place for the RNC?

Multiple law enforcement officials told CBS News that planning is underway to expand the perimeter at the RNC and create buffer zones around the events. The gunman at Saturday's rally opened fire with an AR-style rifle outside the security perimeter set up by Secret Service, law enforcement sources said.

The FBI, Secret Service and local law enforcement agencies sent a joint threat assessment to law enforcement officials in anticipation of the convention calling for heightened awareness. No credible or specific threat was identified in the assessment, a law enforcement source told CBS News.

What happens at the RNC and how does it work?

About 2,400 delegates from around the country will come together to officially nominate Trump during a roll call vote on Monday.

In alphabetical order, states announce how many delegates they will be delivering to each candidate. State party rules affect how delegates may vote during the convention.

But the vote is considered a formality because Trump clinched the nomination in March, amassing the 1,125 delegates needed to become the presumptive nominee. Trump earned 2,243 delegates by the end of the primary process, according to CBS News' estimate.

Trump is expected to officially accept the nomination for the third time since 2016 in a speech on Thursday night.

Besides the pageantry, the Republican Party will adopt a new platform that softens its language on abortion and says the issue should be determined by individual states. The platform also proposes building a missile defense shield over the U.S. and promises tax cuts and mass deportations of people who are in the U.S. illegally.

Where is the Republican convention taking place?

This year's convention is in Milwaukee, Wisconsin, at the Fiserv Forum arena.

Milwaukee is considered a Democratic stronghold, but hosting the convention in Wisconsin, a battleground state, puts the Republican Party's message in front of key voters.

Republicans selected the location in 2022 after former President Donald Trump narrowly won Wisconsin in 2016 before losing it to President Biden in 2020 by a similar margin.

When does the RNC start and end?

The convention begins Monday and ends Thursday. The first official session is scheduled to begin Monday at 12:45 p.m. local time. The marquee speeches will be delivered in the evening on each day.

Who will speak at the 2024 RNC?

The RNC and the Trump campaign released a list of speakers for this week's convention on Saturday, which is made up of lawmakers, television personalities and members of the former president's family, among others.

Names like Tucker Carlson, Vivek Ramaswamy and House Speaker Mike Johnson are on the list, which also includes a number of Republican senators, Senate candidates and representatives.

Trump's wife, Melania Trump, is not among the speakers, nor is his daughter Ivanka Trump. The former president's two older sons are slated to speak, along with his son Donald Jr.'s fiancée Kimberly Guilfoyle, and Lara Trump, who is married to Eric Trump.

Lara Trump , who is also co-chair of the Republican National Committee, teased the lineup earlier this week, saying there will be "unlikely people, celebrities who maybe you've never heard from, who support Donald Trump and support conservative values and the Republican Party." Among the list are country music stars Lee Greenwood and Chris Janson, along with rapper Amber Rose.

Arkansas Sen. Tom Cotton and Florida Rep. Byron Donalds will have prime-time spots, a source with knowledge of the convention's planning told CBS News.

Florida Gov. Ron DeSantis will also give a speech. DeSantis, once considered Trump's most daunting challenger for the nomination, dropped out of the primary in January and quickly endorsed the former president.

Nikki Haley, another Trump primary rival, has also accepted an invitation to speak at the convention, two sources familiar with the planning told CBS News. The development was a reversal from an earlier statement from her spokesperson, who said "she was not invited, and she's fine with that." Before the convention, Haley released the several dozen delegates she won in the primaries and encouraged them to vote for Trump, in the interest of party unity.

Of course, remarks from Trump and his vice presidential pick are the most anticipated. Trump is expected to announce his running mate in the coming days. Ohio Sens. J.D. Vance, Florida Sen. Marco Rubio, South Carolina Sen. Tim Scott and North Dakota Gov.  Burgum are on the shortlist , and all are slated to speak at the convention.

Typically, the vice presidential nominee speaks Wednesday and the presidential nominee addresses the convention on Thursday, the last night of the convention.

How to watch the 2024 RNC with cable

CBS television stations will have coverage beginning at 10 p.m. Eastern during the four days. Find your local CBS station here .

How to watch the 2024 RNC without cable

CBS News 24/7 will have coverage of the convention throughout the day and will stream each night's keynote speeches, and can also be viewed on your mobile or streaming device .

Fin Gómez, Major Garrett and Caitlin Huey-Burns contributed reporting.